Glaucoma is a disease of the eye eventually leading to blindness. It is caused by increasing pressure in the eye. The increase in pressure results from the inability of the aqueous humor to escape through the trabecular meshwork. Two conventional methods of treating open-angle glaucoma include administration of drugs to reduce aqueous humor production to increase outflow and laser trabeculoplasty to increase the aqueous humor outflow. Both of these methods have their limitations.
Recently, a new procedure, transsclera cyclophotocoagulation, has been employed to deactivate portions of the ciliary body to reduce aqueous humor production. Transscleral cyclophotocoagulation involves making several laser burns in the ciliary body. Heretofore the cyclophotocoagulation has been practiced by aiming the laser directly at the conjunctiva and sclera adjacent the limbus. Because the laser traverses the sclera close to the cornea it is desirable to protect the optical portions of the eye from stray laser light. It is also desirable and necessary to hold the eyelids away from the sclera where the laser burns are being made, to compress edematous conjunctiva, to blanch congested conjunctival vessels, and to accurately place the laser beams in relation to the limbus.